In a conventional rotary vane compressor, an intermediate pressure is introduced into backpressure spaces of vanes during operations, so that the vanes are protruded from vane slots. In addition, after stopped, since a pressure in the compressor becomes uniform, forces for protruding the vanes due to the intermediate pressure are not applied. Therefore, a vane whose end edge is directed upward becomes accommodated into a vane slot while lubrication oil in the vane slot is discharged through clearances due to its own weight. When the compressor is activated from the above state, centrifugal forces apply to the vanes so as to protrude them from the vane slots. Volume increase of the backpressure spaces is needed for a vane to protrude from a vane slot, but a lubrication oil amount introduced to the backpressure spaces through the clearances cannot follow and thereby the backpressure spaces have a negative pressure. As a result, the end edge of the vane protrudes insufficiently to contact with an inner wall of a cylinder chamber continuously, so that noises (chattering) may occur due to repeatedly contacting and separating between the inner wall of the cylinder chamber and the vanes.
In a Patent Document 1 listed below, disclosed is a compressor that has a mechanism for preventing chattering. The compressor includes a cylinder chamber with an ellipsoidal inner wall, a rotor rotatably provided in the cylinder chamber, and vanes held in the rotor so as to contact with the inner wall of the cylinder chamber along with a rotation of the rotor.
When the rotor rotates in the cylinder chamber, the vanes are protruded sufficiently from vane slots by biasing forces of coil springs in addition to a centrifugal force, so that end edges of the vanes surely contact with the inner wall of the cylinder chamber. As a result, refrigerant introduced into chambers surrounded by the inner wall of the cylinder chamber and the vanes can be surely compressed.
Namely, in the compressor, the chattering upon activating the compressor is prevented by providing the coil springs.